Marine Ecology

RD3 Seminar

RD3 Seminar 15 October, 2015,  1 p.m. lecture hall westshore building
(Host EV M. Soares)

Prof. WS Grant, Alaska Department of Fish and Game

From molecules to models: history and evolution of DNA data analyses            

The study of natural populations with genetic markers has evolved considerably since the 1970s when protein electrophoresis first enabled studies of statistically large samples. The analysis of genotypic data largely consisted of summary statistics and chi-square tests of frequency differences between samples. The development of restriction fragment length analysis of mitochondrial and DNA sequencing provided still greater resolution of genetic population structure and evolutionary processes. The progress in laboratory methods stimulated new theory and computer programs to analyze data. A pervasive practice in these analyses is the testing of genotypic data against model distributions generated with resampling or coalescence simulations. Models attempt to capture often complex biological processes and hence incorporate numerous simplifying assumptions. Even the Hardy-Weinberg model of random mating makes several that when violated can provide insights into population structure. Coalescence simulations of gene genealogies are used in numerous widely used computer packages. These models can provide estimates of migration and reconstructions of population histories. Two analyses, in particular, are routinely used to analyze mitochondrial DNA sequences: mismatch analysis and Baysian skyline plots (BSPs). BSPs are highly parameterized and make numerous assumptions that are not always considered in the interpretations of the results. Sample design, sample size, natural selection, estimates of mutation rate and the assumption of genealogical bifurcations are especially important variables that conspire to subvert biologically meaningful inferences from BSPs. Erroneous temporal estimates of population events produce a mismatch between supposed population history and climate events and can prevent a clear understanding of mechanisms bringing about micro-evolutionary changes. 






Special Seminar 17. Juli 2015, 11:00 Uhr lecture hall West Shore Building

Dr. Andrew Fidler, Cawthron Institute, Nelson, New Zealand

 "From tunicates to  godwits: a molecular biologist’s on-going attempts to understand  ‘real’ biology"


ABSTRACT: The talk will be somewhat wide-ranging but the  aim is to  describe a number of interesting (I hope!) projects that I have been contributing to over the past few years.  I will first describe the Cawthon  Institute,  a non-government research institute (owned by a public trust) based in little, but sunny, Nelson, New Zealand. I will give an overview  of the  work of the institution with the intention of helping find common interests /  complementary  resources to those of GEOMAR. I will then outline three projects that may be of interest to GEOMAR staff: (1) The use of tunicate xenobiotic receptors as ‘sensor elements’, in recombinant yeast-based bioassays, to detect marine bioactive compounds. (2) Timing of godwit migration departure from New Zealand: application of a ‘candidate gene’ association approach to look for genetic variation that may account for some of the inter-individual variation in migration departure date and (3) Studies on the population genetics of a highly invasive colonial tunicate, Didemnum vexillum.  This third  study has led to an interest in epigenetics, and its possible role in adaptive evolution of marine invertebrates, which motivated me to visit GEOMAR.












back to startpage


Head of the Research Unit:

Prof. Dr. Thorsten Reusch
GEOMAR | Helmholtz Centre for Ocean Research Kiel
West shore Campus
Düsternbrooker Weg 20 
D-24105 Kiel 
Phone: +49-431 600-4550

e-mail: treusch(at)

Personal Assistant / Office Management:

Cornelia Rüther
Phone: +49-431 600-4551
Fax: +49-431 600-134551
e-mail: cruether(at)


Academic Theses